It is known that satellite navigation systems generally allow a terrestrial user to determine his/her position and, optionally, his/her altitude.
However, when the user is located in some places, such as underground passages, buildings, thick forests, etc., it can occur that signals emitted by said satellite navigation systems cannot reach said user, who, as a result, cannot know either his/her position, or his/her orientation.
The aim of the present invention is to overcome such a drawback.